Platen drive device

Abstract

A device for driving a platen includes a motor for driving the platen, and a power transmission mechanism for transmitting the power of the motor to the platen. The power transmission mechanism includes a drive wheel having a pin and driven by the motor for rotation, and a driven wheel having a plurality of grooves in which the pin of the drive wheel is engageable. With this construction, the platen can be rotated and stopped.

What is claimed is: 
     
       1. A device for driving a platen, comprising: a motor; and   power transmission means for transmitting a power output of said motor to the platen, said power transmission means including a Geneva drive wheel having a pin and driven to rotate by said motor, and a Geneva driven wheel having a plurality of grooves in which said pin of said drive wheel is engageable, said drive wheel having a notched portion formed in part of an outer peripheral surface thereof, said notched portion facing said Geneva driven wheel when said motor is stopped to enable manual rotation of said platen.   
     
     
       2. A device for driving a platen, comprising: a ratchet mechanism for retaining a position of the platen when the motor is stopped;   a motor; and   power transmission means for transmitting a power output of said motor to the platen, said power transmission means including a Geneva drive wheel having a pin and driven to rotate by said motor, and a Geneva driven wheel having a plurality of grooves in which said pin of said drive wheel is engageable, said drive wheel having a notched portion formed in part of an outer peripheral surface thereof, said notched portion facing said Geneva driven wheel when said motor is stopped to enable manual rotation of said platen.   
     
     
       3. A device according to claim 2, further comprising braking means for braking said motor when said drive wheel is disengaged from said driven wheel.